Method of applying cyclic urea resins to cellulosic textile materials



United States Patent U 3,218,119 METHOD OF APPLYING CYCLIC UREA RESINS T (ZELLULQSIC TEXTILE MATERIALS William Julius Van Loo, In, Middlesex, N.J., assignor to American Cyanamid Company, Stamford, Comm, a corporation of Maine No Drawing. Filed Feb. 2, 1962, Ser. No. 170,790 5 Claims. (Cl. 8116.3)

This invention relates in general to the treatment of cellulosic textile material with cyclic urea resins and to the improved product obtained thereby. More particularly the invention relates to an improvement in the preparation of cellulosic textiles having a high degree of crease resistance. In its most particular aspect the invention involves impregnation and curing of a cellulosic textile product with a cyclic urea resin in a manner in which the fabric at no time is removed from the treating bath. Such conditions would involve the use of standard dyeing or cleaning establishment equipment.

At the present time aminoplast resins are conventionally applied to the surface of cellulosic textiles in finishing mills or factories by the use of a plurality of treatment steps involving a number of pieces of expensive plant equipment whereby the thermosetting resin is first applied to the textile material from a pad bath or the like, the take-up controlled by a mangle, the water removed from fabric by use of low temperature drying ovens, and finally heated to a temperature of the order of 400 F. in a suitable chamber to cure the resin on the fabric and render it insoluble. The need for such a high curing temperature requires special equipment not normally found in textile dyeing plants and certainly not in the average household. As a necessary consequence of the prior art method of treatment of cellulosic type fabrics the fabric being finished is subjected to a considerable amount of fiber degradation or melting due to the high temperatures employed to impart the resin finish to the surface of the goods. The end result of this is ultimately felt in the diminution of the wearing qualifies of garments prepared from such fibers. The need for a method of finishing a cellulosic type textile material with a satisfactory aminoplast resinous coating which is simple, inexpensive, and which avoids fiber deterioration, is apparent.

It is the principal object of the present invention to disclose a novel means of applying a thermosetting aminoplast resin, specifically a cyclic urea resin to a cellulosic type fabric under reduced conditions of temperature and the use of equipment available in an ordinary dry cleaning plant or in the home.

It is a further object of the present invention to disclose a combination of cyclic urea resins and a class of catalysts which when employed in concert are capable of eifecting a satisfactory thermoset or cure on a cellulosic type textile at reduced temperatures without degrading the cellulosic structure of the textile being treated.

These and other objects of the present invention will become clear upon consideration of the remainder of the specification including the several illustrative examples of the mode of operation of our novel process and its demonstrated advantages.

Accordingly, we have discovered that by the use of a cyclic urea resin of the group consisting of dimethylol ethylene urea and alkylated derivatives thereof in combination with a resin curing catalyst of the group consisting broadly of inorganic salts of metals of Groups II and III of the periodic table, such as aluminum nitrate, zinc nitrate, and the like at temperatures below 250 F. and preferably at temperatures from room temperature to about 250 F. a satisfactory finish of the resin on the fabric can be obtained. This application, because of the low temperature involved, may be conducted in conventional dyeing equipment without the use of equipment needed to impart high temperature to the process. More particular embellishment of this general concept will be recognized as the invention is further illustrated by the specific examples and other elaborating details of the process set forth herein.

In general, the novel process of the invention involves physical application of the resin to the fabric by convenience steeping methods. The best known of these comprises immersing the fabric to be treated in a bath containing one or more of the resins and a catalyst of the type disclosed for a suflicient time to obtain a lwrinkle resistant finish to the textile treated. This treatment time is generally of the order of minutes but will vary somewhat with the selected temperature of the bath and the particular catalyst employed. In such a bath or immersion type process ordinary vats, tubs, kettles, and similar equipment may be employed with equally good result. The reaction temperature will generally be at or near the boiling point of the bath and will range anywhere from about 200 F. to 250 F. depending upon the degree of cure desired and the particular member of our selected resins employed as the finishing agent. For optimum results it has been found that the fabric should be occasionally turned or kept in motion While curing is taking place to insure uniform distribution of the resin being applied to the textile. It is within the scope of the invention to use a number of means for moving the textile to be treated. For example, the movement may be effected by a rotating type apparatus whereby the fabric remains immersed in the liquid as a result of constant contact with a paddle. Alternatively the fabric may be continuously circulated in and out of the treating vat by means of an externally rotating Wheel or drum. As a still further variation fluid movement may be achieved by use of a recirculating pump.

A modification of the process employs a dye-jig. This machine consists of a V-shaped box containing the resin bath and having submerged guide rolls to immerse the fabric in the bath. The machine also contains two drums or beams, on opposite sides and above the surface of the bath. The fabric to be treated is wound on one beam, travels under the guide rolls, into and out of the resin bath, and Winds on to the opposite beam. The machine may be reversed and the fabric run through the bath as many times as are required for adequate cure. Each passage through the machine is called an end. Heat is applied to the bath by means of a jacket heated with steam. In the dye-jig, temperatures of 180 F. and higher may be reached, and the fabric, while out of the bath, is exposed to steam evolving from the heated resin liquor in the dye-jig.

The specific type of equipment employed in the present invention is not restricted. All that is necessary is that the equipment be capable of holding the resin bath and fabric and capable of withstanding heating to about the boiling point of the resin bath. Heat may be applied to the equipment by any convenient means, and movement of the fabric within the resin bath may be eifected by mechanical or manual means but is not, as desired for optimum results, required in all instances.

The resin suitable for use in the present invention must fulfill two requirements: (1) it must be stable to boiling in the presence of a suitable catalyst, and (2) it must be capable of producing the desired fabric property modifications at a temperature essentially equivalent to the boiling point of the resin bath while in the presence of said bath. Many resin types do not possess the required stability when heated to the boil in the presence of a suitable catalyst. Typical of these resin types are the melamine-formaldehyde, al'ylated melamine-formaldehyde, modified melamineformaldehyde, guanamineformaldehyde, and other triazine-formaldehyde resins. These resins are not effective when employed alone, in combination with each other, or in combination with a suitable resin. Among the resin types incapable of producing the desired property modifications at the boiling point of the resin bath and in the presence of said bath, even though possessing the required bath stability, are the urea-formaldehyde, triazone-formaldehyde, and similar a kylated resins and derivatives thereof. For the purposes of the present invention, the cyclic urea-formaldehyde resins have been found to be especially useful and apparently without equivalent. These resins have the following general structure:

wherein all the Rs may be the same or different and may be H or lower alkyl, containing up to about three carbons.

The quantity of resin employed in the treating bath may vary from about 2.5 to about 25 percent solids or more depending upon the degree of fabric property modification desired. A concentration range between and percent solids has been found to be effective.

Catalysts suitable for the present invention generally consist of salts of inorganic acids and metals of Groups II and ill of the Periodic Table, and particularly zinc and aluminum salts. These salts may be used singly or in combination and consist of the chlorides, nitrates, and sulfates or other acid salts. Certain salts of other metals, such as calcium, barium, and magnesium may be employed with the zinc and aluminum salts where desired. The zinc and aluminum salts are generally employed at from about 5 to about percent based on the weight of resin in the application bath. An effective usage range is found to be between 1G and 15 percent.

The advantage derived from using as a catalyst in applicants novel process the inorganic acid salts of metals of Groups ll and E1 of the Periodic Table is that by using these specific catalysts in a long-term curing process in a dye-jig or home bath, unwanted side reactions do not occur. For example, when acid catalysts, such as organic acid catalysts like oxalic acid, are employed the long-term low temperature cure may decompose the catalyst itself. it may, instead of curing the resin on the fabric, cause the resin to polymerize to an uncontrolled degree where it resists bonding and the like. In the case of other catalysts, formaldehyde is depleted from the resin to react with an ammonium ion to form hexamethylene tetraamine which also hinders proper bonding as well as the depletion of formaldehyde interfering with the function of the resin itself.

The heat treatment to efiect desirable fabric property modifications involving the application bath and fabric will vary somewhat depending upon the concentration of resin, the concentration and specific catalyst, the temperature, and the time employed. The temperature employed will generally range from about 168 to about 212 F. or higher, depending upon the boiling point of the application bath. Times of from about 69 to about 180 minutes are generally required to complete the heat treatment, with the shorter times pertaining to the higher temperatures. Where aluminum salts are employed as catalysts, the time required to complete the heat treatment is generally shorter than where zinc salts are employed.

When the heat treatment is completed, the fabric is removed from the bath. The fabric may then be allowed to dry at room temperature as is, but it is greatly preferred to rinse the fabric in cold water first to remove excess resin and catalyst prior to such drying. When dry, the

lfabric will be found to have improved properties, particularly improved wrinkle recovery.

The following examples are given by way of illustration of the present invention and are not intended to limit the thereof. All parts indicated therein are by weight unless otherwise specified.

Example 1 .Applications of ethylene-urea rosin A solution containing 18 percent resin solids is prepared by dissolving lOO parts solids of dimethylol ethyleneurea and 12 parts of zinc nitrate (anhydrous basis) in water and diluting to a total of 1,000 parts with water. Cotton percale, 30 X 80, is immersed in this solution which is then heated to the boil (approximately 212 F.) and held at that point for 150 minutes during which time additions of water are made to maintain the original liquor volume. The fabric is then removed from the bath, rinsed in cold water, squeezed to reduce the water content of the fabric to about percent of its original dry weight, and allowed to dry at room temperature.

Wet and dry wrinkle recoveries are obtained on the treated fabric. The wrinkle recovery is measured on a Monsanto Wrinkle Recovery Tester following tentative test method No. 66-1956 described on page 158 of the 1957 Technical Manual and Yearbook of the American Association of Textile Chemists and Colorists, volume 33. The fabric is saturated with water prior to making a wet wrinkle recovery measurement. The results of the tests are as follows:

TABLE 1 Wrinkle recovery total W & F in degrees Untreated 138 Wet wrinkle recovery 219 Dry wrinkle recovery .243

This example demonstrates that dimethylol ethyleneurea and zinc nitrate can effectively improve fabric wrinkle recovery when the fabric is immersed in the treating bath and said bath boiled, in this case for minutes. T

Example 2.Czzrz'ng dimetliylol ethylene urea resin on fabric in a boiling bar/z; comparison of zinc and aluminum nitrate catalysts Solution A.One hundred parts of resin solids of dimethylol ethyleneurea and 12 parts of zinc nitrate (anhydrous basis) are dissolved in sufficient water to make a total of 1,000 parts.

Solution B.-Same as A with 12 parts of aluminum nitrate (anhydrous basis) instead of zinc nitrate.

Cotton percale, 80 X 80, is immersed in each of the above solutions, the temperature of which is then raised to the boil and held at that point for 60 minutes during which time water is added to maintain the original volume. The fabrics are then removed, rinsed in cold water, squeezed, and dried at room temperature.

The wrinkle recovery is measured by the method of Example 1. The tensile strength of the treated fabrics is measured on a Scott Tensile Tester according to ASTM Test D-39. The results are shown in Table II below:

This example demonstrates that 60 minutes is insufficient to obta n high wrinkle recovery with the boiling barns of the resin-catalyst systems employed, but that aluminum nitrate is more effective than zinc nitrate for the time employed.

Example 3.C0mparis0n of urea formaldehyde vs. cyclic urea resin Solutions containing percent solids of each of the following resins are prepared by dissolving 400 parts of resin solids and 48 parts of zinc nitrate (anhydrous basis) in water and diluting each solution to a total of 4,000 parts with water.

A. Dimethylol ethyleneurea B. Dimethylol urea C. Bis (methoxymethyl) urea The above resin solutions are applied to 80 x 80 cotton percale using a dye-jig, heating to the boil over a five minute interval, and boiling for 60 minutes. The fabric is transported at the rate of yards per minute. At the end of this time the resin bath is emptied out and the dye-jig filled with cold water in which the treated fabric is run to remove excess resin and catalyst. The fabric is then allowed to dry at room temperature.

For comparative purposes, the same resin baths are applied to the fabric by padding employing a wet pick-up of 100 percent. These fabrics are dried for 2 minutes at 225 F. and cured for 1.5 minutes at 350 F. using conventional finishing plant equipment.

The wrinkle recovery (dry) is measured as described in Example 1 and the tensile strength, as described in Example 2.

Analysis for nitrogen (Kjeldahl) is made on the treated fabrics before and after boiling in Water for minutes. The percentage of resin originally on the fabrics and that present after boiling are calculated. The percentage of resin fixed on fabric determined in this manner is also calculated.

The various results are shown below in Table III.

TABLE III Application method and cure Resin employed Dye-jig Pad 350 F. cure Monsanto wrinkle recovery, total W 8: F in degrees:

A 235 288 B 185 257 197 274 Untreated (138) Tensile strength W dz F in pounds:

A 88 53 B 101 C 86 51 Untreated (113) Resin on fabric after cure (percent):

K 7. 9 8. 6 B 14. 7 8. 7 C 7 7 9. 5 Resin on fabric after wash (percent):

A 5. 2 6. 4 B 9. 1 7. 4 C 5.1 8. 6 Resin fixation (percent):

A 66 74 B 62 C 66 Resins employed:

A.Dimethy1o1 ethyleneur'ea. B.-Dimetlr ylol urea C.Bis (methoxyrnethyl) urea This example demonstrates that dimethylol ethyleneurea can be applied and cured effectively on a dye-jig. The Wrinkle recovery effected upon the dye-jig is surprisingly high even though it is not equivalent to that obtained under dry cure conditions, but a lower amount of resin is fixed by the dye-jig than by dry curing and may be responsible for the lower wrinkle recovery improvement observed.

This example further demonstrates that although dimethylol urea and bis(methoxymethyl)urea may be fixed on fabric by the dye-jig application, wrinkle recovery improvement is of a low order. It must be remembered that the amount of resin fixed on fabric is not necessarily a measure of the wrinkle recovery imparted to fabric because it depends in large measure to the method of fixation of the resin to the fabric. Thus, resin may be polymerized upon fabric or engaged monofunctional reaction with cellulose, both of which conditions would lead to fixed resin. However, only that resin engaged in cross-linking of cellulose is thought to contribute greatly to wrinkle recovery. Apparently under the conditions of applicants application, cross-linking is obtained with dimethylol ethyleneurea but not with dimethylol urea or bis(methoxymethyl)urea.

Example 4 Solutions containing 10 percent solids of each of the following resins are prepared according to the procedure given in Example 3.

D. Dimethylol melamine E. 2,4-bis(methoxymethylamino)-S-hydroxymethylamino- 1,3,5-triazine F. 1,3-hydroxymethyl-5-ethyltetrahydrotriazinone-2 Applications are attempted as in Example 3. As the baths with fabric therein containing resins D and E are brought to the boil resin precipitation occurs, resulting in an uneven surface deposition of resin polymer. The fabrics are discarded since the treatment is highly undesirable. Resin F runs satisfactorily through the dye-jig and subsequent operations, but the dried treated fabric has a wrinkle recovery of 154 and a resin fixation of 25 percent when tested as in Example 3. Corresponding values for the resin applied by the dry cure procedure were 283 wrinkle recovery and 82 percent resin fixation.

This example demonstrates that melamine formaldehyde resins cannot be run by the process of the present invention because of instability at the boil in the presence of the desired catalyst. It also demonstrates that triazone resins do not produce desirable wrinkle improvement under the conditions employed and are fixed on fabric to a very minor extent.

I claim:

1. In a method in which the cellulosic textile material being treated is maintained substantially in continuous contact with a treating solution throughout a period of reaction sufliciently to cure such treated cellulosic textile material, said method for applying a cyclic urea resin to cellulosic textile materials comprising reacting said cyclic urea resin with said cellulose textile material by substantially simultaneously steeping and curing the cellulosic textile materials in said treating solutions of (1) a cyclic urea resin selected from the group consisting of dimethylol ethylene urea and alkylated ethers thereof and (2) a resin curing catalyst consisting of an inorganic acid salt of a metal selected from Groups II and III of the Periodic Table while substantially maintaining the temperature of said cure at from about F. up to less than 250 F. for the duration of said steeping, said duration of steeping ranging from about 60 minutes to about 180 minutes.

2. A method according to claim 1 wherein the resin curing catalyst is zinc nitrate.

3. A method according to claim 2 wherein the temperature of cure is 212 F.

4. A method according to claim 3 wherein 5 to 25 percent of the resin curing catalyst based on the weight of said resin in said reactant solution is employed.

5. A method for applying dimethylol ethyleneurea to cellulosic textile materials for creaseproofing said materials which comprises steeping the textile material in a solution containing 100 parts of dimethylol ethyleneurea and 12 parts of zinc nitrate per 1,000 parts of total soluperature.

6 tion at a temperature of 212 F, 01 150 minutes in 21 2,763,574 9/1956 Rllperti 8116.3 bath, removing and evaporating to dryness at room tem- 2,974,065 3/1961 Mann et a1. 8116.3 X 3,046,079 7/1962 Reeves et a1 8116.3 3,050,419 8/1962 Ruperti 8-1163 Refereniles Citefl by 111% Exammdl 5 3,084,071 4/1963 Van Loo 117-1394 UNITED STATES PATENTS 7/193" Rivat s 116 2 OTHER REFERENCES 1/193; Q EZiZIZZZIZ Prick at 211., Textile Research Journal, v01. XXIX, No. 2 1949 widmgr 3 115 3 P g April 1959- 2 22 NORMAN G. TORCHIN, Primary Examiner. 5/1955 Burks 8-4163 JULIAN S. LEVITT, Examiner. 

1. IN A METHOD IN WHICH THE CELLULOSIC TEXTILE MATERIAL BEING TREATED IS MAINTAINED SUBSTANTIALLY IN CONTINUOUS CONTACT WITH A TREATING SOLUTION THROUGHOUT A PERIOD OF REACTION SUFFICIETNLY TO CURE SUCH TREATED CELLULSOIC TEXTILE MATERIAL, SAID METHOD FOR APPLYING A CYCLIC UREA RESIN TO CELLULOSIC TEXTILE MATERIALS COMPRISING REACTING SAID CYCLIC UREA RESIN WITH SAID CELLULOSE TEXTILE MATERIAL BY SUBSTANTIALLY SIMULTANEOUSLY STEEPING AND CURING THE CELLULOSIC TEXTILE MATERIALS IN SAID TREATING SOLUTIONS OF (1) A CYCLIC UREA RESIN SELECTED FROM THE GROUP CONSISTING OF DIMETHYLOL ETHYLENE UREA AND ALKYLATED ETHERS THEREOF AND (2) A RESIN CURING CATALYST CONSISTING OF AN INORGANIC ACID SALT OF A METAL SELECTED FROM GROUPS II AND III OF THE PERIODIC TABLE WHILE SUBSTANTIALLY MAINTAINING THE TEMERPATURE OF SAID CURE AT FROM ABOUT 160*F. UP TO LESS THAN 250*F. FOR THE DURATION OF SAID STEEPING, SAID DURATION OF STEEPING RANGING FROM ABOUT 60 MINUTES TO ABOUT 180 MINUTES. 